scholarly journals miR-26a/HOXC9 Dysregulation Promotes Metastasis and Stem Cell-Like Phenotype of Gastric Cancer

2018 ◽  
Vol 49 (4) ◽  
pp. 1659-1676 ◽  
Author(s):  
Xudong Peng ◽  
Qingjie Kang ◽  
Rui Wan ◽  
Ziwei Wang
Keyword(s):  
Gastric Cancer ◽  
Stem Cell ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Loss Of Function ◽  
Promoting Effect ◽  
In Vivo Experiments ◽  
Direct Target ◽  
Cancer Tissues

Background/Aims: Previous studies demonstrated that HOXC9 acts as an oncogene in several tumors. The aim of this study was to explore whether HOXC9 promotes gastric cancer (GC) progression and elucidate the underlying molecular mechanisms. Methods: HOXC9 expression in GC tissues and adjacent non-cancer tissues was detected by quantitative RT-PCR (qRT-PCR) and immunohistochemistry. The functional effects of HOXC9 on proliferation, metastasis and stem cell-like phenotype were evaluated by relevant experiments in GC cells. The effect of miR-26a on HOXC9 was investigated by gain- and loss-of-function assays and luciferase reporter assay. Nude mouse models were established to test the effect of miR-26a and HOXC9 on tumorigenesis and metastasis of GC cells in vivo. Results: Herein, we showed that HOXC9 was upregulated in GC tissues and associated with a poor prognosis. HOXC9 knockdown inhibited the metastasis and stem cell-like phenotype of GC cells without significant effects on cell proliferation. In addition, we identifed HOXC9 as a direct target of miR-26a. Restoration of miR-26a in GC cells downregulated HOXC9 and reversed its promoting effect on metastasis and self-renewal, whereas miR-26a silencing upregulated HOXC9. In vivo experiments showed that HOXC9 knockdown suppressed tumorigenesis and lung metastasis of GC cells in nude mice, and these effects were mimicked by restoration of miR-26a. Conclusion: The present study demonstrates that HOXC9 promotes the metastasis and stem cell-like phenotype of GC cells, and this phenomenon can be reversed by restoration of miR-26a.

scholarly journals TEAD4 modulated LncRNA MNX1-AS1 contributes to gastric cancer progression partly through suppressing BTG2 and activating BCL2

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
You Shuai ◽  
Zhonghua Ma ◽  
Weitao Liu ◽  
Tao Yu ◽  
Changsheng Yan ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Mechanistic Model ◽  
Ectopic Expression ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Tissue Samples ◽  
Reporter Assays

Abstract Background Gastric cancer (GC) is the third leading cause of cancer-related mortality globally. Long noncoding RNAs (lncRNAs) are dysregulated in obvious malignancies including GC and exploring the regulatory mechanisms underlying their expression is an attractive research area. However, these molecular mechanisms require further clarification, especially upstream mechanisms. Methods LncRNA MNX1-AS1 expression in GC tissue samples was investigated via microarray analysis and further determined in a cohort of GC tissues via quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. Cell proliferation and flow cytometry assays were performed to confirm the roles of MNX1-AS1 in GC proliferation, cell cycle regulation, and apoptosis. The influence of MNX1-AS1 on GC cell migration and invasion was explored with Transwell assays. A xenograft tumour model was established to verify the effects of MNX1-AS1 on in vivo tumourigenesis. The TEAD4-involved upstream regulatory mechanism of MNX1-AS1 was explored through ChIP and luciferase reporter assays. The mechanistic model of MNX1-AS1 in regulating gene expression was further detected by subcellular fractionation, FISH, RIP, ChIP and luciferase reporter assays. Results It was found that MNX1-AS1 displayed obvious upregulation in GC tissue samples and cell lines, and ectopic expression of MNX1-AS1 predicted poor clinical outcomes for patients with GC. Overexpressed MNX1-AS1 expression promoted proliferation, migration and invasion of GC cells markedly, whereas decreased MNX1-AS1 expression elicited the opposite effects. Consistent with the in vitro results, MNX1-AS1 depletion effectively inhibited the growth of xenograft tumour in vivo. Mechanistically, TEAD4 directly bound the promoter region of MNX1-AS1 and stimulated the transcription of MNX1-AS1. Furthermore, MNX1-AS1 can sponge miR-6785-5p to upregulate the expression of BCL2 in GC cells. Meanwhile, MNX1-AS1 suppressed the transcription of BTG2 by recruiting polycomb repressive complex 2 to BTG2 promoter regions. Conclusions Our findings demonstrate that MNX1-AS1 may be able to serve as a prognostic indicator in GC patients and that TEAD4-activatd MNX1-AS1 can promote GC progression through EZH2/BTG2 and miR-6785-5p/BCL2 axes, implicating it as a novel and potent target for the treatment of GC.

scholarly journals PITPNA-AS1 Activated by H3K27ac Sponged miR-98-5p to Regulate Cisplatin Resistance in Gastric Cancer

2021 ◽  
Author(s):  
Yaping Liu ◽  
Xu Zhao ◽  
Yinnan Chen ◽  
Gang Guo ◽  
Jiansheng Wang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Proliferation ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Platinum Resistance ◽  
Luciferase Reporter Gene ◽  
Gene Assay ◽  
Proliferation And Apoptosis ◽  
Gastric Cancer Cell Lines ◽  
Cancer Tissues

Abstract To evaluate the expression of PITPNA-AS1 and miR-98-5p in gastric cancer tissues as well as their association with progression of gastric cancer, and investigate the role of PITPNA-AS1 and miR-98-5p in developing platinum resistance. RNA sequencing was used to identify candidate lncRNAs and microRNAs related to local recurrence of gastric cancer. qRT-PCR was used to investigate the expression of PITPNA-AS1 and miR-98-5p. CCK-8 and caspase3/7 activity were used to evaluate the cell proliferation and apoptosis rate. Dual luciferase reporter gene assay and RNA pull down were used to evaluate the cross talk between PITPNA-AS1 and miR-98-5p. PITPNA-AS1 and miR-98-5p could regulate cell proliferation and inhibit apoptosis in gastric cancer cell lines. Cisplatin and lobaplatin could significantly suppress the expression of PITPNA-AS1, which interacted with negatively regulated miR-98-5p expression. PITPNA-AS1 overexpression impaired the effect of platinum, which was partially reversed by downregulation of miR-98-5p knock down. In gastric cancer, PITPNA-AS1 and miR-98-5p could regulat cell growth, apoptosis and platinum resistance. They have the potential to be biomarkers and curative therapeutic targets. However, further research on molecular mechanisms are needed.

scholarly journals Cyclin D3-CDK6 Complex Facilitates Tumorigenesis by Regulating the C-Myc/miR-15a/16 Axis in a Feedback Loop in Gastric Cancer

2020 ◽  
Author(s):  
Yeting Hong ◽  
Wei He ◽  
Jianbin Zhang ◽  
Lu Shen ◽  
Chong Yu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Feedback Loop ◽  
Cell Cycle Progression ◽  
Molecular Mechanisms ◽  
Cyclin D3 ◽  
Luciferase Reporter

Abstract Background: Cyclin D3-CDK6 complex is a component of the core cell cycle machinery that regulates cell proliferation. By using Human Protein Atlas database, a higher expression level of this complex was found in gastric cancer. However, the function of this complex in gastric cancer remain poorly understood. This study aims to determine the expression pattern of this complex in gastric cancer and to investigate its biological role during tumorigenesis.Methods: To demonstrate that Cyclin D3-CDK6 regulate the c-Myc/miR-15a/16 axis in a feedback loop in gastric cancer, a series of methods were conducted both in vitro and in vivo experiments, including qRT-PCR, western blot analysis, EdU assay, flow cytometry, luciferase reporter assay and immunohistochemical staining. SPSS and Graphpad prism software were used for data analysis.Results: In this study, we found that Cyclin D3 and CDK6 were significantly upregulated in gastric cancer and correlated with poorer overall survival. Further study proved that this complex significantly promoted cell proliferation and cell cycle progression in vitro and accelerated xenografted tumor growth in vivo. Furthermore, we explored the molecular mechanisms through which the complex mediated Rb phosphorylation and then promoted c-Myc expression in vitro, we also found c-Myc could suppress miR-15a/16 expression in gastric cancer cell. Finally, we found that miR-15a/16 can simultaneously regulate Cyclin D3 and CDK6 expression as direct target genes.Conclusions: Our findings uncover the Cyclin D3-CDK6/c-Myc/miR-15a/16 feedback loop axis as a pivotal role in the regulation of gastric cancer tumorigenesis, and this regulating axis may provide a potential therapeutic target for gastric cancer treatment.

scholarly journals OTUB2 Facilitates Tumorigenesis of Gastric Cancer Through Promoting KDM1A-Mediated Stem Cell-Like Properties

2021 ◽  
Vol 11 ◽  
Author(s):  
Guangming Liu ◽  
Wei Guo ◽  
Junjie Qin ◽  
Zhiliang Lin
Keyword(s):  
Gastric Cancer ◽  
Stem Cell ◽  
Survival Rates ◽  
Histone Demethylase ◽  
Deubiquitinating Enzyme ◽  
Stem Cell Markers ◽  
Loss Of Function ◽  
Sphere Formation

Otubain 2 (OTUB2), a deubiquitinating enzyme, overexpression is considered to predict poor outcome in various cancers. However, the function and potential regulatory mechanisms of OTUB2 in gastric cancer (GC) progression remains unclear. To determine how OTUB2 participate in GC progression, the gain and loss of-function experiments were conducted in vivo and in vitro. We found that OTUB2 was upregulated in GC samples (n=140) and cells. Moreover, the overall, first progression and post progression survival rates of GC patients with high OTUB2 expression showed a poorer prognosis than that in those patients with low OTUB2 expression. Down-regulation of OTUB2 suppressed sphere formation and reduced expression of stem cell markers in GC cells. Furthermore, OTUB2-silenced GC cells also showed a decreased proliferation, invasion, migration, and in vivo tumorigenic ability. However, OTUB2 overexpression showed the opposite effects. Notably, we demonstrated that OTUB2 increased lysine-specific histone demethylase 1A (KDM1A) expression through deubiquitination. KDM1A, a demethylase known to promote demethylation of downstream genes, was identified to promote the maintenance of cancer stem cell characteristics. Moreover, the alterations caused by OTUB2 overexpression were partly inversed by KDM1A knockdown and in turn KDM1A overexpression reversed the changes induced by OTUB2 shRNA. Taken together, we demonstrate that OTUB2 may serve as a vital driver in GC tumorigenesis by enhancing KDM1A-mediated stem cell-like properties.

scholarly journals MiR-144-3p inhibits gastric cancer progression and stemness via directly targeting GLI2 involved in hedgehog pathway

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yixun Lu ◽  
Benlong Zhang ◽  
Baohua Wang ◽  
Di Wu ◽  
Chuang Wang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Flow Cytometry ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Gastric Cancer Cells ◽  
Cancer Tissues ◽  
Gastric Cancer Progression

Abstract Background Gastric cancer (GC) is the fifth most commonly diagnosed cancer worldwide. Due to the dismal prognosis, identifying novel therapeutic targets in GC is urgently needed. Evidences have shown that miRNAs played critical roles in the regulation of tumor initiation and progression. GLI family zinc finger 2 (GLI2) has been reported to be up-regulated and facilitate cancer progression in multiple malignancies. In this study, we focused on identifying GLI2-targeted miRNAs and clarifying the underlying mechanism in GC. Methods Paired fresh gastric cancer tissues were collected from gastrectomy patients. GLI2 and miRNAs expression were detected in gastric cancer tissues and cell lines. Bioinformatics analysis was used to predict GLI2-targeted miRNAs and dual-luciferase reporter assay was applied for target verification. CCK-8, clone formation, transwell and flow cytometry were carried out to determine the proliferation, migration, invasion and cell cycle of gastric cancer cells. Tumorsphere formation assay and flow cytometry were performed to detail the stemness of gastric cancer stem cells (GCSCs). Xenograft models in nude mice were established to investigate the role of the miR-144-3p in vivo. Results GLI2 was frequently upregulated in GC and indicated a poor survival. Meanwhile, miR-144-3p was downregulated and negatively correlated with GLI2 in GC. GLI2 was a direct target gene of miR-144-3p. MiR-144-3p overexpression inhibited proliferation, migration and invasion of gastric cancer cells. Enhanced miR-144-3p expression inhibited tumorsphere formation and CD44 expression of GCSCs. Restoration of GLI2 expression partly reversed the suppressive effect of miR-144-3p. Xenograft assay showed that miR-144-3p could inhibit the tumorigenesis of GC in vivo. Conclusions MiR-144-3p was downregulated and served as an essential tumor suppressor in GC. Mechanistically, miR-144-3p inhibited gastric cancer progression and stemness by, at least in part, regulating GLI2 expression.

scholarly journals LGR4 Maintains HGSOC Cell Epithelial Phenotype and Stem-Like Traits

2020 ◽  
Author(s):  
Zhuo Wang ◽  
Ping Yin ◽  
Yu Sun ◽  
Lei Na ◽  
Jian Gao ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Luciferase Reporter ◽  
Ovarian Cancer Cells ◽  
Sox2 Expression ◽  
In Vivo Experiments ◽  
Epithelial Phenotype ◽  
Reporter Assays ◽  
Regulatory Loop ◽  
Cancer Tissues

Abstract Background: High-grade serous ovarian cancer (HGSOC) is lethal mainly due to extensive metastasis. Cancer cell stem-like properties are responsible for HGSOC metastasis. LGR4, a G-protein-coupled receptor, is involved in the maintenance of stem cell self-renewal and activity in some human organs. Methods: TCGA and CCLE database was interrogated for gene mRNA analysis in ovarian cancer tissues and cell lines. The interactions between LGR4 and ELF3 were validated through dual-luciferase reporter assays, Chip assays and Co-IP assays. Gain- and loss-of functions of LGR4, ELF3, FZD5 and WNT7B were performed to identify their roles in the behaviors of ovarian cancer cells. Flowcytometry analysis and tumorisphere formation assays were performed to identified their stem-like properties. In vivo experiments were performed as well.Results: LGR4 was shown to be overexpressed in HGSOCs and maintain the epithelial phenotype of HGSOC cells. LGR4 knockdown suppressed POU5F1, SOX2, PROM1 (CD133) and ALDH1A2 expression. Furthermore, LGR4 knockdown reduced CD133+ and ALDH+ subpopulations and impaired tumorisphere formation. To the contrary, LGR4 overexpression enhanced POU5F1 and SOX2 expression and tumorisphere formation capacity. LGR4 knockdown inhibited HGSOC cell growth and peritoneal seeding in xenograft models. Mechanistically, LGR4 and ELF3, an epithelium-specific transcription factor, formed a reciprocal regulatory loop, which was positively modulated by WNT7B/FZD5 pair. Consistently, knockdown of ELF3, WNT7B, and FZD5, respectively, disrupted HGSOC cell epithelial phenotype and stem-like properties. Conclusion: Together, these data demonstrate that WNT7B/FZD5-LGR4/ELF3 axis maintains HGSOC cell epithelial phenotype and stem-like traits; targeting this axis may prevent HGSOC metastasis.

scholarly journals Cir-ITCH inhibits gastric cancer migration, invasion and proliferation by regulating the Wnt/β-catenin pathway

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yang Peng ◽  
Hong Hong Wang
Keyword(s):  
Gastric Cancer ◽  
Lymph Node ◽  
Lymph Node Metastasis ◽  
Cancer Prognosis ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Node Metastasis ◽  
Cancer Tissues

Abstract Circular RNAs (circRNAs) are differentially expressed in various tumours, but the expression and regulatory mechanisms of circular RNA ITCH (cir-ITCH) in gastric cancer remain unclear. For this reason, in the present study, we assessed the expression of cir-ITCH and the associated regulatory mechanism of cir-ITCH in gastric cancer. Through RTq-PCR assays, we observed that cir-ITCH expression was attenuated in gastric cancer cell lines and tissues, with cir-ITCH expression in gastric cancer tissues with lymph node metastasis being considerably lower than that observed in gastric cancer tissues without lymph node metastasis. In addition, we demonstrated that cir-ITCH or linear ITCH may be a useful marker for gastric cancer prognosis by Kaplan–Meier survival analysis. We also showed that cir-ITCH overexpression could increase linear ITCH expression through miR-17 via RNA immunoprecipitation (RIP) and luciferase reporter assays. Moreover, in vivo and in vitro experimental results showed that cir-ITCH can act as a tumour suppressor to prevent gastric cancer tumourgenesis by sponging miR-17. The Wnt/β-catenin pathway plays a crucial role during the carcinogenesis of cancers, and we observed that cir-ITCH could negatively regulate Wnt/β-catenin signalling, which could be restored by miR-17. In summary, cir-ITCH was shown to prevent gastric cancer tumourgenesis through the Wnt/β-catenin signalling pathway by sequestering miR-17.

scholarly journals miR-362-3p acts as a tumor suppressor by targeting SERBP1 in ovarian cancer

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shujun Cao ◽  
Na Li ◽  
Xihong Liao
Keyword(s):  
Ovarian Cancer ◽  
Cell Proliferation ◽  
Cancer Progression ◽  
Target Gene ◽  
Molecular Mechanisms ◽  
Gynecological Cancer ◽  
Luciferase Reporter ◽  
Loss Of Function

Abstract Background Ovarian cancer is the leading lethal gynecological cancer and is generally diagnosed during late-stage presentation. In addition, patients with ovarian cancer still face a low 5-year survival rate. Thus, innovative molecular targeting agents are required to overcome this disease. The present study aimed to explore the function of miR-362-3p and the underlying molecular mechanisms influencing ovarian cancer progression. Methods The expression levels of miR-362-3p were determined using qRT-PCR. Gain-of-function and loss-of-function methods were used to detect the effects of miR-362-3p on cell proliferation, cell migration, and tumor metastasis in ovarian cancer. A luciferase reporter assay was performed to confirm the potential target of miR-362-3p, and a rescue experiment was employed to verify the effect of miR-362-3p on ovarian cancer by regulating its target gene. Results miR-362-3p was significantly downregulated in ovarian cancer tissues and cell lines. In vitro, our data showed that miR-362-3p suppressed cell proliferation and migration. In vivo, miR-362-3p inhibited ovarian cancer growth and metastasis. Mechanistically, SERBP1 was identified as a direct target and functional effector of miR-362-3p in ovarian cancer. Moreover, SERBP1 overexpression rescued the biological function of miR-362-3p. Conclusions Our data reveal that miR-362-3p has an inhibitory effect on ovarian cancer. miR-362-3p inhibits the development and progression of ovarian cancer by directly binding its target gene SERBP1.

scholarly journals LncRNA LINC00342 promotes gastric cancer progression by targeting the miR-545-5p/CNPY2 axis

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Run Liu ◽  
Xianwu Yang
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Growth Factor Signaling ◽  
Ags Cells

Abstract Background This study aimed to explore the role and underlying molecular mechanisms of long non-coding RNA (lncRNA) LINC00342 in gastric cancer (GC). Methods The expression of LINC00342 in GC tissues was evaluated by Quantitative reverse transcription polymerase chain reaction (qRT-PCR). Silencing of LINC00342 was conducted to investigate the effect of LINC00342 in vitro and in vivo. The underlying molecular mechanisms of LINC00342 were determined by dual luciferase reporter assay, Western blotting analysis and rescue experiments. Biological functions of LINC00342 were evaluated by cell counting kit-8 (CCK-8) assay, colony formation assay, wound healing assay and Transwell assays. In addition, a tumor model was used to verify the effect of LINC00342 in tumorigenesis in vivo. Results LINC00342 was significantly upregulated in GC tissues and cell lines. Silencing of LINC00342 efficiently inhibited proliferation, migration and invasion of AGS cells in vitro, and also suppressed the tumorigenesis of GC in vivo. Functional experiments showed that LINC00342 regulated the expression of canopy fibroblast growth factor signaling regulator 2 (CNPY2) by competitively sponging miR-545-5p. Rescue experiments showed that inhibition of miR-545-5p and overexpression of CNPY2 significantly reversed cell phenotypes caused by silencing of LINC00342. Conclusion LINC00342 plays a potential oncogenic role in GC by targeting the miR545-5p/CNPY2 axis, and might act as a novel therapeutic target for GC.

scholarly journals Circular RNA circLMO7 acts as a microRNA-30a-3p sponge to promote gastric cancer progression via the WNT2/β-Catenin pathway

2020 ◽  
Author(s):  
Jiacheng Cao ◽  
Xing Zhang ◽  
Penghui Xu ◽  
Haixiao Wang ◽  
Sen Wang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Noncoding Rna ◽  
Target Gene ◽  
Molecular Mechanisms ◽  
Glutamine Metabolism ◽  
Diagnosis And Treatment ◽  
Luciferase Reporter ◽  
Migration And Invasion

Abstract Background : Gastric cancer (GC) is one of the most common malignant tumors worldwide. Currently, the overall survival rate of GC is still unsatisfactory despite progress in diagnosis and treatment. Therefore, studying the molecular mechanisms involved in GC is vital for diagnosis and treatment. CircRNAs, a type of noncoding RNA, have been proven to act as miRNA sponges that can widely regulate various cancers. By this mechanism, circRNA can regulate tumors at the genetic level by releasing miRNA from inhibiting its target genes. The WNT2/β-Catenin regulatory pathway is one of the canonical signaling pathways in tumors. It can not only promote the development of tumors but also provide energy for tumor growth through cell metabolism (such as glutamine metabolism). Methods: Through RNA sequencing, we found that hsa_circ_0008259 (circLMO7) was highly expressed in GC tissues. After verifying the circular characteristics of circLMO7, we determined the downstream miRNA (miR-30a-3p) of circLMO7 by RNA pull-down and luciferase reporter assays. We verified the effect of circLMO7 and miR-30a-3p on GC cells through a series of functional experiments, including colony formation, 5-ethynyl-2’-deoxyuridine and Transwell assays. Through Western blot and immunofluorescence analyses, we found that WNT2 was the downstream target gene of miR-30a-3p and further confirmed that the circLMO7-miR-30a-3p-WNT2 axis could promote the development of GC. In addition, measurement of related metabolites confirmed that this axis could also provide energy for the growth of GC cells through glutamine metabolism. We found that circLMO7 could promote the growth and metastasis of GC in vivo by the establishment of nude mouse models. Finally, we also demonstrated that HNRNPL could bind to the flanking introns of the circLMO7 exons to promote circLMO7 cyclization. Results: CircLMO7 acted as a miR-30a-3p sponge affecting the WNT2/β-Catenin pathway to promote the proliferation, migration and invasion of GC cells. Moreover, animal results also showed that circLMO7 could promote GC growth and metastasis in vivo . CircLMO7 could also affect the glutamine metabolism of GC cells through the WNT2/β-Catenin pathway to promote its malignant biological function. In addition, we proved that HNRNPL could promote the self-cyclization of circLMO7. Conclusions: CircLMO7 promotes the development of GC by releasing the inhibitory effect of miR-30a-3p on its target gene WNT2.

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